Carpenter&#39;s level



Nov. 19, 1929; R. B. MADDOX 1,736,502

CARPENTERS LEVEL Filed Sept. 6, 1927 g 1 ll ATTORNEY8 Patented Nov. 19, 1929 UNITED STATES ROBERT B. MADDOX, OF ELK, CALIFORNIA CARPENTER S LEVEL Application filed September 6, 1927. Serial No. 217,698.

The present invention relates to improvements in carpenters levels and its main object is to simplify the construction of a level of the character described by reducing the number of bulbs usually employed for taking vertical and horizontal readings to a single one.

It is particularly proposed in the present invention to provide in combination with the well-known straight edge of a carpenters level a circular bulb allowing a reading to be conveniently taken with the straight edge, whether disposed vertically or horizontally.

Further objects and advantages of my invention will appear as the specification proceeds.

The preferred form of my invention is illustrated in the accompanying drawing, in which Figure 1 shows aplan View of a carpenters level made in accordance with my invention;

Figure 2, a section taken along line 2-2 of Figure 1; and

Figure 3, a view similar to that of Figure l, but showing the level in actual use in connection with a vertical element.

l/Vhile I have shown only the preferred form of the invention, I wish to have it understood that various changes or modifications may be made within the scope of the claim hereto attached without departing from the spirit of the invention.

In its preferred form my carpenters level comprises the conventional bar 1 having one or more straight edges 2, and a bulb 3 mounted within the confines of said bar. The bulb is preferably made in the form of a circular ring allowing a liquid contained therein to seek its level on opposite sides no matter what position the level occupies.

The circular bulb may be mounted in the bar 1 in any suitable manner, for instance as illustrated in Figure 2 where the ringshaped bulb is shown as being inserted through a cylindrical aperture l in the center of the bar to come to reston an internal shoulder 5, and as being held in place by two frustro-conical holding members 6 resting on frustro-conical seats 5' and bearing on opposite faces of the bulb and secured by screws 7.

Markings 8 are provided on the bar itself or the frustro-conical elements secured thereto, and not on the bulb as is now the common practice. The markings preferably include two lines on opposite sides of the bulb and running parallel to one of the straight edges, and two other lines arranged at right angles to the former lines.

The bulb is filled with liquid to one-half of its capacity, so that when one of the straight edges 2 is disposed horizontally, the surface of the liquid within the bulb is readable with two of the lines, and when the straight edge is disposed vertically the surface of the liquid is readable with the other two lines.

It should be understood that the form of the bulb may be changed to some extent without a departure from the present invention, although I consider the circular ring shown in the drawing as the best embodiment of my idea. Any other form of ring or endless tube, or symmetrical hollow body allowing the liquid level to be readily compared with the markings on the bar, might allow the function to be performed in a similar manner. The advantages of this form of level may be readily understood from the foregoing description. The fact that the markings are provided on the bar instead of on the bulb facilitates the assembly of the device since no attention need be paid to the positioning of the bulb apart from the proper centering of the same. The use of a single bulb for both horizontal and vertical surfaces makes the entire device more simple sections and bearing on the bulb for holding the same in place and means for securing the latter elements to their seats, the bulb being visible from opposite sides of the straight edge and no part of the holding means projecting beyond the surface thereof.

ROBERT B. MADDOX. 

